Controlling electric motor.



No. 7l4,786. Patented Dec. 2, I902.

. M. W. DAY.

CONTROLLING ELECTRIC MOTORS.

(Application filed Sept. 26, 1900.

(No Model.) 2 Sheets-Sheet I.

Fig. 2.

Inventor:

Wmnesse Maxwell WDH No. 714,786. 7 Patented Dec. 2. I902 M. W. DAY.

CONTROLLING ELECTRIC MOTORS.

(Application filed Sept. 26, 1900.;

2 Sheets-Sheet 2.

' (Nu Iodel.)

Mtness es:

UNITED STATES PATENT OEEIcE.

MAXlVELL WV. DAY, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

CONTROLLING ELECTRIC MOTOR.

SPECIFICATION forming part of Letters Patent No. 714,786, dated December2, 1902. Application filed SeptemberZB, 1900. Serial No. 31,132. (Nomodel.)

To whom it may concern: is effected by means of a rheostat forming a Beit known that I, MAXWELL W. DAY, a part of the transmitting apparatus ofthe syscitizen of theUnitedStates,residingat Schentem and to whichmotion is communicated ectady, county of Schenectady, State of New bythe helmsman or other operator. The ar- 5 York, have invented certainnew and useful mature of the motor 1 is indicated at 8, andImprovementsin Controlling Electric Motors, its terminals are connectedto suitable leads (Case No. 1,215,) of which the following is a 9 and10, extending from the armature 11 of specification. the power-drivengenerator 12. The field of My present invention relates to means forthis generator is represented at 13, the cur- IO controlling electricmotors from a distance, rent for exciting the field being derived fromand comprises certain improvements of parthe ships mains 6 7 andregulated by means ticular value for use in connection with the of arhe'ostat 14 under the control of the steering of ships, the value ofthese improvehelmsman. When the rudder-actuating momen ts being,however, not limited to the partor has been started into operation, acertain 15 ticular application of the same mentioned. means is providedfor progressively shutting The invention comprises certain arrangeoff ortendingto shut off the current supplied ments of apparatus and ofelectric circuits, to the field of the generator 12, and consetogetherwith certain details of construction, quently the current supplied tothe armature all of which will be set forth with particuof therudder-actuating motor. This means 2o larity in the followingdescription and accomconsists of a synchronous electrical transpanyingdrawings, the features of novelty bemission device, which acts to moveone meming pointed out in the appended claims. ber of thecontrolling-rheostat in a reverse In the drawings, Figure 1 represents adiadirection in synchronism with the movegram of a system of motorcontrol arranged ments of the ships rudder, so that there is 25 inaccordance with my invention. Fig. 2 is at all times a definite fixedrelation between an end elevation of a transmitting apparatus themovements of the rudder-actuating motor forming part of my motorcontrolsystem. and the member of the controlling-rheostat. Figs. 3 and 4: areviews of a modified form of This transmission device consists of asyntransmitting apparatus, while Figs. 5-, 6, and chronous motor gearedto one member of the 3o 7 are detail views of said modified form oftransmitting apparatus and electrically contransmitting apparatus.nected through a multiconductor-cable with The broad features of themotor-control a device which is controlled by the movesystem may be bestunderstood by referring ments of the rudder and acts through the cafirstto Fig. 1. In the system there repreble to produce arotating polarityinthe field 35 sented the rudder-actuating mechanism used of thesynchronous motor. The synchronous for ship-steering purposes consistsof a .momotor is shown at 17 and consists of a fixed tor 1, having, itsshaft geared by means of a and a rotatable member, the fixed member worm2 with a cooperating worm-gear 3, atresembling a gram-ring having aplurality of tached to the shaft 4, connected to the rndconductorsleading from equally-spaced a 40 der. This motor 1 has its field-winding5 0011- points in the length of the winding, these constantly excitedfrom a source of constant podoctors beinggrouped together, so as to formtential-such, for example, as the mains 6 7, a multiconductor-cable,which extends into leading to the electric-power-generating sysproximityto the rudder-actuating mechantem of the ship. The speed of the motor,as ism. The rotating member of the synchro- 5 45 well as its torque, isvaried by varying the nous motor consists of a direct-currentfieldelectromotive force impressed upon its armamagnet 18, excited bycurrent derived from ture, the requisite variations of electromotive anysuitable source-as, for example, the force being obtained by supplyingthe armaships mains 6 7. The six conductors 19 to ture from adirect-current generator, the volt- 24:, which extend fromequally-spaced points 50 age of which is varied by varying its fieldexin the ring 17 and which are grouped together citation. This variationof field excitation to form the multiconductor-cable 25, are connectedto equally-spaced points in a closedcircuit rheostat 26. This rheostatis connected at short intervals in its length to the segments of acommutator 27. Over this commutator sweep two diametrically-locatedbrushes 28 and 29, connected, respectively, through collector-rings withleads 30 and 31, extending to the ships main 6 7. The shaft carryingthese diametrically-extending contacts 28 29 is geared to the shaft ofthe rudder by suitable gearing, (indicated conventionally at 32.

The operation of the motor-control system may now be roughly describedas follows: The operator at the transmitting mechanism first causes themovable contacts 33 34 to be moved away from their neutral position onthe commutator 35, the segments of which are connected to points on therheostat 14, as shown. The result is that an electromotive force ofgradually-increasing value is impressed upon the field of the generator12, thereby gradually building up the said field and causing thegeneration in the armature of this machine of an electromotive force ofcorrespondingly-varying character, which electromotive force isimpressed upon the armature of the rudder-actuating motor 1. This motorimmediately starts into operation and moves the rudder away from itsneutral position. This movement of the rudder, however, acting throughthe gearing 32, causes a corresponding movement of the arm carrying themovable contacts 28 29. The result is a corresponding shifting ofpolarity around the ring 26, this shifting polarity being transmittedelectrically through the multiconductorcable 25 to the fixed member 17of the synchronous motor. The shifting polarity or rotating field, asitmay conveniently be termed, thus causes a corresponding rotation of themovable member 18 of the synchronous motor, this rotation beingsynchronous with and having a definite relation to the rotation of therudder itself. The motion of the movable member of the synchronous motoris communicated through gearing of some suitable type, such as willhereinafter be described, and causes or tends to cause a return of thecontacts 33 34 to their neutral position on the commutator 35, thusgradually cutting down the generator-field. This neutral position be ingreached, the current supplied by the generator 12 ceases and the rudderstops.

The fact that the machine 12 is a generator is indicated by the belt anddriving pulley shown in conventional diagram connected thereto.

One form of transmitting apparatus forcontrolling the field of thegenerator 12 is shown in Fig. 2. It consists of a commutator 35,

secured to a suitable framework 36. The segments of this commutator areconnected to two rheostats 37, corresponding to the two sections of therheostat 14 shown in Fig. 1, the connections between the commutator andrheostats being, however, omitted in Fig. 2

for the sake of clearness of illustration. Brushes or contacts 33 34bear upon commutator 35 and are carried by an arm 38, secured to a shaft39, movable in bearings in the framework 36. Motion is communicated tothe shaft through the cooperation of four bevel-gears, two of which, 39"and 40, are mounted upon oppositely-extending pins carried by a hub 41,keyed to said shaft. Of the other two bevel-gears one (indicated at 42)is secured to the steering-wheel 43, which is free to rotate about thesaid shaft. Similarly the other bevel-gear 44 is rotatable about thesaid shaft and is secured to a toothed gear 45, connected through anintermediate gear 46 with a shaft 47, carrying the rotating member of asynchronous motor. This rotating member is in Fig. 2 concealed behindthe fixed member 48; but its construction will readily be understood byreference to its representation at 18, Fig. 1. Ourrentis supplied tothis rotating member through collectorrings 49 and cooperating brushesand leads, which for convenience are not shown. In order to limit thenumber of revolutions of the steering-wheel 43, and thereby limit theangle through which the rudder may be turned, I make use of a stoppingdevice consisting of two gear-wheels, one fixed to the steering-wheel 43and designated by the numeral 50, the other meshing therewith andindicated at 51. This latter gear-wheel is provided with a pin 52, whichafter a sufficient amount of rotation of the wheel comes into engagementwith the teeth of the pinion 50, thereby acting as a stop and preventingany further movement of the steering-wheel.

The illustration of the transmitting apparatus in Fig. 2 shows the partsin their middle or neutral position corresponding to the middle orneutral position of the rudder. In this position of rest the movablemember of the synchronous motor is held with comparative rigidity in agiven position with respect to its fixed member. Under thesecircumstancesarotation of the steering-wheel causes a rotation of thebevel-gear 42, the bevel-gear 44 at this moment resisting any rotationby reason of its geared connection with the movable member of saidsynchronous motor,which thereby acts as a sort of fulcrum. The result isa forward movement of the oppositelymounted bevel-gears 39 and 40,carried by the shaft 39. The resulting movement of this shaft causes arotation of the contact-arin 38, carrying the contacts or brushes 33 34,which cooperate with the rheostat-commutator 35. This movement of thebrushes over the segments of the commutator and away from the neutralposition (indicated in diagram in Fig. 1) immediately causes anelectromotive force to be impressed upon the generator, which operatesthe rudder-actuating motor. This motor then starts up and by means ofthe gearing shown at 32 in Fig. 1 shifts the points of connection of theleads 3O 31 along the ring-winding of the rheostatic device 26, therebyshifting points of opposite polarity from one set of leads emanatingtherefrom to the next, and so on, this shifting polarity beingtransmitted by these leads through the multiconductor-cable 25 to thefixed member 17 of the synchronous motor. The revolving member of thismotor immediately starts up and runs in synchronism with the shifting ofpolarity aboutits fixed member. The revolving member of this motor isgeared, by means of the toothed gear 46, with the gear-wheel 45, whichis loose on the shaft 39, but which carries the bevel-gear 44, meshingwith the two revolving beve1- gears 39 and 40. The intermediate gearingreferred to is so arranged. as to cause bevelgear 44 when put intooperation to rotate in a direction opposite the direction of rotation ofthe steering-wheel 43. The effect of this rotation of the bevel-gear 44is to return the contact-carrying arm 38 to its neutral position, thebevel-gear 42 under these circumstances being prevented by the helmsmanfrom revolving backward, as the synchronous motor produces a reactionthereon when it starts into operation.

The figures on Sheet 2 are views more or less in detail of a differentform of ransmitting apparatus, the operation of which, however, is thesame in function as that of the transmitting device in Fig. 2. Fig. 4 isa view of the transmitting apparatus, taken from a position facing thesteering-wheel. Fig. 3 is another view of the apparatus, taken partly incross-section along the line X Y. The steering-wheel in thismodification is indicated at 53 and is fixed to a screw-threaded shaft,(shown in detail at 54 in Fig. 7 and also at 54 in Fig. 6.) Thisscrew-threaded shaft carries a bevel-gear 55 pinned thereto, this gearmeshing with a companion gear 56, mounted on the top end of a verticaltransmitting-shaft extending below the deck 58;

which supports the wheel-box 59. The lower end of this shaft 57transmits motion through a pair of bevel-gears 60 to a horizontal shaft61. This shaft carries an intermediate gear 62, which meshes with alarge gear 63 on a shaft 64, which carries one of the two relativelyrevolving members of a rheostat, the function of which is indicated moreclearly in Fig. 1. The parts of the rheostat carried by this shaftconsist of two sections of resistance mounted in retaining-boxes 65 66,pinned to the shaft. The various terminals leading from these sectionsof resistance connect to a commutator 67, likewise pinned upon the sameshaft, the connections corresponding to those indicated in Fig. 1. Theother member of the rheostat consists of two cont-acts or brushes 68 69,movable over the segments of the commutator 67, these contacts orbrushes being carried by a gear-wheel 70. (Shown in Fig. 3 and in detailin Fig. 5.) Electrical connections between these contacts or brushes andthe leads extending to the field 13 of the generator (shown in Fig. 1)

are secured in this case by means of collector-rings 71 and cooperatingbrushes. (Not shown.) In order to communicate motion to the brushes orcontacts 68 69 from the movable member of the synchronous motor 72,corresponding to the synchronous motor 48 in Fig. 2, I mount upon theshaft 73 of this movable member a spur-gear 74, which meshes with thegear 70, carrying the moving brushes 68 and 69. This arrangement ofparts is indicated better in Fig. 5, which represents a partial viewofthe transmitting apparatus, taken from a position facing the right-handend of the view shown in Fig. 3. In this Fig. 5 the fixed member of thesynchronous motor is shown at 72, the rotating member being indicated at75, while the gear mounted upon the same shaft as the rotating member 75is likewise indicated at 74. The gear with which the gear 74 cooperatesis indicated at and is the same as the gear shown at 70 in Fig. 3. Thedirect-current excitation of the movable member 75 of the synchronousmotor is secured by transmitting current to the movable member throughleads connected to cooperating brushes and collector rings, (shown at76,) this current being supplied from any suitable source-such, forexample, as the ships mains 6 7. The permanent electrical connectionbetween the ships mains 6 7 and the two sections of the rheostat 65 66is similarly obtained through other collectorrings 77 and cooperatingbrushes and leads. (Not shown.) These permanent connections correspondto the connections of the leads 15 16 with therheostat shown in Fig. 1.Sliding connections between the mains and rheostats are needed in Fig.3, because the rheostats revolve, while in Fig. 2 no sliding connectionsare necessary, because the rheostats are fixed in position.

In order to indicate to the helmsman the direction and amount ofmovement of the rudder, I make use of an indicating device locatedwithin the presence of the helmsman and acted upon through gearingconnecting with the shaft 73 of the synchronous motor. This indicatingdevice comprises a screwthreaded shaft 78, mounted on the top of thesteering-box 59, parallel and in proximity to the shaft 54. The shaft 78is connected by bet el-gearing through the vertical shaft 79 with theshaft 73 of the synchronous motor. Upon both of the threaded shafts 54and 78 are traversing nuts 80 81, these nuts carrying pointers movingover a scale 82. Lugs 86, carried by the shaft 54, engage similar lugson the sliding nut 80, so as to limit the range of movement of thelatter, and consequently therange of movement ofthe steering- Wheel.When the steering-wheel is moved in either direction, the sliding nut 80is moved along the scale 82, while at the same time motion istransmitted through the shaft 57 and intermediate gearing to the gear63, mounted upon the rheostat-shaft. The commutator 67 of the rheostatis thus moved under the brushes which bear thereon, thereby transmittinga current to the driving-generator for the steering-motor, as will beclearly understood by reference to the diagram in Fig. 1. Thesteering-motor immediately starts into operation, thereby transmittingmotion electrically to the synchronous motor in the manner alreadydescribed. This motor immediately start-s into operation and immediatelyreturns or tends to return the brushes 68 and 69 to the same relativeposition which they previously occupied upon the rheostat-com mutator67. In doing so the rotation of the shaft 73 transmits motion throughthe bevelgears 83, the upright shaft 79, and the bevelgears 84 to theshaft '78, carrying the sliding nut 81. This nut is immediatelytraversed along the shaft, and the mechanical connections are arrangedso that its direction of m 0- tion causes it to move toward the newposition assumed by the nut 80 due to the rotation of thesteering-wheel. When the relatively moving parts of the rheostat havebeen moved by the synchronous motor into the relative positioncorresponding to the relation of parts shown in Fig. 1 and convenientlyknown as a steady position, the rudder-motor ceases to rotate, therebystopping the synchronous motor, and consequently the parts gearedtherewith. The gearing is such that when the steering-motor stops thesliding nut 81, driven by the synchronous motor, stops in a positionopposite the sliding nut 80, driven by the steering-wheel 53. Themovements of the sliding nut 81 and its position upon the scale 82therefore serve to indicate the position of the rudder at any moment andalso whether its movements have or have not caught up to thosev of thesteering-wheel, as indicated by the movement of the sliding nut 80driven thereby.

I do not claim, broadly, the combination, witha motor, of a controllingdevice for starting and stopping said motor located at a point distanttherefrom, together with means for operating said device to start themotor, and electrical means arranged to move synchronously with saidmotor for operating said device to stop the motor, since such broadcombination is not of my invention.

What I do claim as new, and desire to secure by Letters Patent of theUnited States, 1s

1. The combination of a motor, agenerator electrically connectedthereto, manually-controlled means for gradually building up the fieldof said generator in either direction, and a synchronous electromotivedevice operatively connected to the said motor and arranged to operatein synchronism therewith to gradually cut down the field of the saidgenerator.

2. The combination of a motor, a generator electrically connectedthereto, man ually-con trolled means for supplying current to thefield-winding of said generator in either direction, and a synchronouselectromotive device which operates in synchronism with said motor toshut off the supply of current to the field-winding of the saidgenerator.

3. The combination of a rheostat, a manually-controlled device forproducing a relative movement of cooperating parts of the rheostat, anda synchronousmotive device acting to return the parts of the rheostat totheir original relative position.

4. The combination of a motor, a generator for supplying currentthereto, a rheostat for controlling the current delivered by thegenerator, a manually-controlled device for producing a relativemovement of the cooperating parts of the rheostat, and electrical meansoperating synchronously with said motor and actingto return the parts ofthe rheostat to their original relative position.

5. The combination of a motor, arheostat,

a manually-controlled device for producing a relative movement ofcooperating parts of the rheostat, and electrical means operatingsynchronously with said motor and acting to return the parts of therheostat to their original relative positions.

6. In a steering apparatus, the combination of a rudder-actuating motor,a generator for supplying energy thereto, and a rheostat for thegenerator-field cooperatively acted on by the helmsman and by motioncommunicated through movement of the rudder.

7. In a steering apparatus, the combination of a rudder-actuating motor,a generator for supplying energy thereto, a rheostat for the field ofthe generator, manually-controlled means for operating the rheostat inone direction, and means responsive to movement of said motor forreturning the parts of the rheostat to the off position.

8. The combination of a motor, a generator for supplying currentthereto, a rheostat for controlling the current supplied by thegenerator, manually-controlled means for moving one member of therheostat in one direction, and means responsive to movement of the motorfor moving said member in the reverse direction.

9. The combination of a motor, a generator for supplying currentthereto, a rheostat for controlling the current supplied by thegenera-tor, manually-controlled means for moving one member of therheostat in one direction, and means operating synchronously with saidmotor for moving said member in the re verse direction.

10. In a steering apparatus, the combination of a steering wheel, ascrew driven pointer for indicating the displacement of thesteering-wheel, and a pointer for indicating the position of the rudder.

In witness whereof I have hereunto set my hand this 22d day ofSeptember, 1900.

MAXl/VELL WV. DAY.

Witnesses:

EENJAMIN B. HULL, FRED Ross.

IIO

